Electric metal-working



2 SheetsSheet 1.

(No Model.)

H. LEMP & W. S. MOODY.

ELEOTRIO METAL WORKING.

No. 515,778. Patented Mar. 6, 1894.

(No Model.) 2 Sheets-Sheet 2.

H. LEMP & W. S. MOODY. BLEGTRIC METAL WORKING.

No. 515,778. Patented Mar. 6, 1894.

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rmamn Lamp 1 a ter 45'. Moody fit orney- UNITED STATES PATENT OFFICE.

HERMANN LEMP, OF LYNN, AND IVALTER S. MOODY, OF CHELSEA, MASSA-CHUSETTS, ASSIGNORS TO THE THOMSON ELECTRIC \VELDING COMPANY,

OF MAINE.

ELECTRIC METAL-WORKING.

SPECIFICATION forming part of Letters Patent No. 515,778, dated March 6,1894.

Application filed May 26,1891. Serial Nor 394,215. (No modeL) To Mr?whom it may concern:

Be it known that we, HERMANN LEMP, a resident of Lynn, in the county ofEssex, and WALTER S. MoonY, a resident of Chelsea, in

the county of Sufifolk, State of Massachusetts,

citizens of the United States, have invented a certain new and usefulProcess of Electric Metal-Working, of which the following is aspecification.

Our invention relates to metal working operations wherein electricity isemployed as the means for heating the work to the desired temperature,and has special reference to that class of work wherein the piece orpieces to be operated upon by being included in an electric circuit areof different sizes or material or wherein a single piece is acted uponand is of different size or conductivity at opposite ends or portions.

Our invention is designed especially with reference to the electricwelding of metal pieces end to end wherein one piece is of greater sizeor conductivity than the other, and the object is to provide a means foradjusting or determining the flow of current in the two pieces so thatthey shall heat at the proper rate.

Our invention consists essentially in including the two pieces to bewelded in a circuit between the terminals of a divided source ofelectric energy and connecting the work between the terminals with anintermediate point of the divided source or sources and adjusting therelative potential of the two sides 3 5 or portions of the'sourceaccording to the conductivity of the pieces to be joined.

Our invention consists further in a construction of electric metalworking apparatus adapted to be used in carrying out our in- 40 ventionand more particularly to a construction wherein the source of heatingcurrents is a transformer the secondary of which consists of a body ofmetal of large mass or cross section.

In the accompanying drawings Figure l we have shown in side elevation aform of apparatus embodying our novel construction of apparatus, andsuitable for use in practicing the method or process of welding herein5o claimed. Fig. 2, represents the secondary bar or conductor strippedof its appurtenances, and Fig. 3, represents a cross section of theentire apparatus taken on the plane indicated by line 3, 3, in Fig. 2.

A, A, indicate respectively the terminals of a source or sources ofelectric energy adapted to supply current which will flow from one tothe other of said terminals. These terminals or electrodes are providedwith suitable means for holding the work to be operated upon and arearranged in line with one another, as indicated, and have means wherebyeither or both may be moved in the linejoining them so as to subject thework held between them to end pressure.

The secondary bar or conductor as more clearly shown in Figs. 2 and 3,is formed of three vertical portions joined at their lower ends andbearing at their upper ends the terminals A, A and IV. Rectangularopenings C, C, are provided for the reception of the usual iron cores15, and about these openings are formed recesses or channels D, D, forthe reception of the primary coils 12, 13. The cores are generallyformed of plates of sheet iron out and put together in any convenientmanner. The manner of constructing and applying the coils and cores maybe varied without departing from our invention. Upon the terminals A, A,are mounted in any suitable manner the necessary work holders. In thepresentinstance said holders are shown as formed of blocks mounted in adove-tailslide and carrying the common form of screw and lever clamp. Atthe terminal V, a similar work-holder may be mounted but in the presentinstance we have shown said terminal provided with the adjustablecontacts L, L. This terminal W, stands as a terminal common to the twosecondaries, whose other terminals are, respectively, A, A.

Ye have herein shown the work holding devices as consisting of suitableclamps adapted to hold two pieces 2 24, which are to be welded togetherand are both provided with 5 means for moving the work holder or thework which is in connection with the terminals A, A, so as to subject itto the end pressure requisite in the welding or other operation. Thedevices for these purposes may be 100 varied indefinitely withoutdeparting from our invention and would necessarily be modified accordingto the particular welding work to be done. Though we have shown theholders as having pieces 23, 24, to be joined together end to end byabutt welding process, we do not limit ourselves to that class of workand as will hereinafter appear the apparatus might be used in the sameway if the work consisted of a continuous piece of metal placed betweenthe holders to be heated by the current and of greater cross section atone end than at the other.

The electrode W, is connected to an intermediate point of the source orsources of electric energy whose extreme opposite poles are connectionis made with such larger piece by' means of the contact connected to theterminal W, so as to bring such larger piece in connection with anintermediate point or point of division of the source and the potentialis increased on that side of the divided source or sources which isjoined immediately to the larger piece, as to terminal A, thus causingthe current to flow in part from or to the point of division of the,source through the work connected thereto or from the work to the pointof division, on well known principles, so that the larger piece will beheated not only by the current which passes across from one extreme poleof the source or sources A, to the other extreme pole A, but also by thecurrent passing to or from the point of division of the source, whilethe other pieceor portion of the work connected to the terminal A, willbe heated only by that part of the current which passes from oneterminal A, to the other A.

The adjustment of the relative potential of the two sides of the sourceat opposite sides of the point of division may be done in any desiredway without departing from our invention. v

In the present case we have shown the source of energy as consisting ofthe secondary bar S, of a transformer the two opposite electric poles orterminals of which secondary consist of the terminals A, A, while themass of metal W, is an intermediate pole or projection from the metalbar or secondary circuit. Toadjnst the relativepotential of the twosides of the source thus provided we preferably apply upon the bar, ateach side of the intermediate pole or terminal, two primary coils andiron cores as indicated, inducing coils or primaries and iron coresbeing indicated at 12, 1, the same being applied to said bar orconductor S, in any proper manner to induce secondary currents in thesaid conductor in the same direction which currents will flow in seriesfrom one terminal A, through the work to the other A, and then throughthe bar S, as a pole to terminal A. If, however, a greater current isflowing in the primary 13, than in the primary 12, there will not onlybe a current through the bar S, from end to end and across from A, to A,through the work, but there will be a current from A, through the righthand portion of bar S, to W, and from W, to A, through the correspondingportion of the work. If the heaviercurrent be through primary 12, then adivision of the current will be from W, through the left hand portion ofbar S, to A, and through the corresponding portion of the work to Theprimary circuits may be supplied with alternating currents from anysource desired and to vary the relative potential of the two sides ofthe secondary, we provide, preferably, means for regulating the flow ofcurrent in each primary, suchas indicated at I. The regulating devicemay be of any desired character known in the art. By increasing-therelative flow of current in the two primary conductors by the regulatingapparatus a greater or less amount of current may be made to flowthrough the intermediate pole W, and

complete its circuit on which ever side of the secondary is given thehigher potential.

It will be obvious that our invention might be employed in the same waywhen the pieces of material are the same in size but have differentspecific conductivities owing to the difference in the nature of thematerial.

Our invention could be employed also in regulating the relative heatingof the two ends of a continuous piece of metal placed between theelectrodes A, A, and larger at one end than at the other.

Our invention might be so used in case it was desired to form an upsetor expansion at an intermediate portion of a tapering bar of metalincluded between the two movable holders of the apparatus which holderswould be moved toward one another to subject the bar to end pressure andupset the material after heating by the current. In such a case if themetal were subjected to the action of a current in the ordinary waypassed entirely from one terminal to the otherit would heat only at thesmaller end near the holder and might melt at its point of attachmentinstead of becoming plastic uniformly between the clamps or at thecentral point between them. We instance this merely as an example of theapplications of the apparatus.

The special construction of the transformer ,itself and the means forsecuring the difference of potential in the two sides or portionsthereof, we do not herein claim as they form the subject of claims inanother application for patent filed by us of even date herewith. Nor dowe claim herein the improvement in electric metal working consisting inheating the metal at any point by subjecting it to the simultaneousaction of currents passed into or through it at an angle to one anotheras this forms the subject of broad claims in our prior application filedOctober 20, 1890, Serial No. 368,695.

What we claim as our invention is 1. The herein described improvement inelectric welding consisting in including the two pieces to be welded inthe circuit between terminals of a divided source or sources of electricenergy, connecting the work between said terminals with an intermediatepoint of the source or sources, and adjusting the relative potential ofthe two sides or portions of the source or sources to the relative sizeor conductivity of the pieces to be joined.

2. The herein described improvement in electric welding, consisting inincluding the pieces to be welded in a circuit between the terminals ofa divided source or sources of energy, connecting the pieces to bejoined with a point of division of said source, and increasing thecurrent flow through the piece requiring a greater current by raisingthe potential of the side of the divided source connected thereto.

3. The herein described improvement in welding metals electrically,consisting in including the two pieces while in abutment in a circuitbetween the two terminals of a secondary bar or conductor, connectingthat metal piece which requires the greater current to an intermediatepart of said secondary bar or conductor, inducing in the two sides ofthe said secondary bar or conductor at opposite sides of suchintermediate portion alternating electric currents of the samedirection, and producing a greater potential in that side of thesecondary bar which is connected to the piece requiring a greatercurrent.

4. The combination in an electric welding apparatus, of two work holdersarranged in line and provided with means for applying end pressure tothe pieces between them, a source or sources of energy connected inseries to said holders, and means for connecting the work to anintermediate point or points of division of said source or sources, asand for the purpose described.

5. The combination in an electric metal working apparatus, of two workholders or electrodes arranged in line and provided with means formoving one or both in a direction toward one another, a divided sourceor sources of energy connected to the same, means for connecting thework to a point of division of the source, and means for adj usting therelative potential of the two sides or portions of the source atopposite sides of the point of connection of the work therewith.

6. The combination in an electric welding apparatus, of two work holdersarranged in line and forming respectively the terminals of a source orsources of heating current, and two contacts or electrodes connectedwith an intermediate point or point of division of said source, andadapted to make connection with the work in either holder at pleasure.

7. The combination in an electric metal working apparatus with asecondary bar or conductor, of two adjustable contacts in electricalconnection with an intermediate part of said bar or conductor andadapted to bear upon the work placed between the terminals of suchsecondary.

8. The combination in an electric welding apparatus, of two primaryconductors, a secondary or conductorin which the said primaries inducecurrents in the same direction, means for holding the parts to be weldedin electrical connection with the terminals of said secondary, andcontacts or connections from an intermediate portion of said secondarybetween the two primaries, as and for the purpose described.

Signed at Lynn, in the county of Essex and State oflVIassacl1usetts,this 18th day of May, A. D. 1891.

HERMANN LEMP. WALTER S. MOODY.

Witnesses:

JOHN W. GIBBONEY, WARREN B. LEwIs.

